In my anecdotal experience, anyway.
I agree with all of this. A glass of wine or a beer used to be a reliable way for me to limber up before writing. I stopped drinking nearly 4 years ago and it's impacted my writing in many ways, but the first that struck me was how much more writing I could get done. When I stopped, I had a ton of new time on my hands and I've frequently been able to fill that with work or thinking about work.